The difference between ultra-thin disc grinding wheels of different colors

There are countless models of grinding wheels on the market now, maybe you see more color classification of grinding wheels, the common ones are black and green, so what is the difference between these two colors?
First of all, the materials of the two grinding wheels are different. The black grinding wheel is generally brown corundum, and the white grinding wheel is generally silicon carbide. Secondly, the characteristics of the two grinding wheels are different. The manufacturer said that the black grinding wheel is made of brown corundum, and the firing temperature is higher than that of the green grinding wheel. Therefore, it is very wear-resistant and durable. The firing temperature of the green grinding wheel is relatively low, so it is not as durable as the black ultra-thin disc grinding wheel. However, due to its silicon carbide material, the green grinding wheel is very sharp and its cutting efficiency is higher than that of the black grinding wheel.